Ainz wins this so easily that I am not joking when I say that he could solo SAO. Ainz is really haxed and has so many insta kill spells that it is not even funny I looked up in the LN that one of his strongest spells killed 70k soldiers instantly and on top of that made some very powerful monsters as a side effect from killing so many people these monsters were called the dark young and had lvl higher than 90 at the same time Ainz broke the world record for summoning so many at one time. You will see in the anime when the fight with Shalltear comes up another powerful death spell. Ainz class is a special class that was primarily focused on death magic and thus very haxed.